Gas-discharge nozzle for use in furnaces



Sept 1957 K. c. GEHRING GAS-DISCHARGE NOZZLE FOR USE IN FURNACES 2 Sheets-Sheet 1 Filed July 3, 1956 56 ER 8: l

I m g MN 535 kmkvk his Attorney.

Sept. 24, 1957 K C GEHRING 2,807,506

GAS-DISCHARGE NOZZLE FOR USE IN FURNACES Filed July 3, 195,6 2 Sheets-Sheet 2 I/VVENTOR. KURT C GEHR/IVG,

his .Atfomeyf GAS-DISCHARGE NOZZLE non USE IN FURNACES Kurt C. Gehring, Chicago, Ill., assignor to United States Steel Corporation, a corporation ofNew Jersey Application July 3, itsa stsn Nb; 595,678

claims: or; 299- 131 This invention relates generally to apparatus for discharging a gas jet and, more particularly, to a nozzle for the oxygen lance used in the open-hearth furnace for making steel.

The use of oxygent in the open-hearth furnace presents a serious problem in respect to the nozzle of the supply tube or lance which is inserted through a hole in the furnace roof, because the nozzle must be lowered to within a short distance of the furnace charge and is subjected for substantial periods of time to extremely high-temperature conditions, e. g., 6000 F. Water cooling of the lance and nozzle is, of course, necessary but even with such protection, the nozzle suffers considerable deterioration and must be replaced eventually. A constant flow of water in large volume must be maintained particularly at the extreme end of the nozzle, to provide adequate cooling. The possibility of leakage constitutes a serious hazard since water exposed to the temperature in the furnace vaporizes with explosive force. There is also the possibility that the nozzle may be damaged by being accidentally brought into contact with the furnace charge.

I have invented a gas-jet nozzle particularly adapted for oxygen lances used in open-hearth furnaces, with novel provisions for insuring adequate cooling and preventing leakage of cooling water yet permitting ready replacement when deterioration of the nozzle becomes evident, in order to avoid destructive explosions as a result of nozzle failure. In a preferred embodiment, I utilize an oxygen-supply pipe having a cooling-water jacket in the form of a cylindrical tube surrounding it, with a coaxial baffle tube therein. A cup-shaped nozzle head or shell fits in the end of the water chamber and is provided with a central cup spaced from the peripheral wall thereof, which has a sealed sliding fit on the end of the oxygen pipe. One or more jet tubes extend from the cup through the shell. A sleeve removably seated at the end of the baflie tube extends forwardly to a plane closely adjacent the extreme end of the nozzle head.

A complete understanding of the invention may be obtained from the following detailed description and explanation which refer to the accompanying drawings illustrating the present preferred embodiment. In the drawings:

Figure l is a central, longitudinal section through a lance provided with my improved nozzle;

Figure 2 is a similar section through the bafiie sleeve alone;

Figure 3 is an end elevation thereof;

Figure 4 is a view similar to Figure 1 showing a slight modification; and

Figure 5 is a rear end elevation of the nozzle of Figure 4.

Referring now in detail-to the drawings and for the present, to Figures 1 through 3, an oxygen-supply pipe has a fitting 11 at one end adapted to make connection with a flexible hose leading to a source of gas. A collar 12 adjacent the fitting 11 affords a mounting for a baflle 2,30?,506 Patented Sept. 24, 1957 "ice tube :13 isurrounding pipeilobut spaced therefrom. A

similar collar J14 on tube 13 affords a mounting for a tubular water ehamberifi surrounding the baflle tube and spaced therefrom. Circumferentially spaced centering lugs lti adjacent the; forward ends of pipe 10, baflle 13 and chamber 15, which are substantially coterminous, maintain the proper spacing therebetween. I A water inlet 17 extends laterally from baflle 13 adjacent collar 12 and an outlet 13 fromchamber adjacent collar 14.

Afcup shaped nozzle head or shell 19 in the form of I a; cylinder. with a rounded end 20 fits snugly in the end of tubular chamber 15- and isbrazedthereto at 21. cup-shaped terminal 22 has" a sliding fit on the end of tube 10 which is turned down slightly to enter the hub, and is provided with circumferential grooves to accommodate sealing rings 23. The end wall of the terminal is drilled and tapped to receive one or more jet tubes 24 screwed therein and extending through holes in the end 20 of shell 19 and Welded thereto.

A sleeve 25 fits snugly in the end of baflie tube 13 which is counterbored as at 26 and has an inturned flange 27 at its forward end. The flange is notched, as shown at 28 in Figure 3, so as to fit loosely about the exterior of tubes 24. Flange 27 has circumferentially spaced studs 29 extending forwardly therefrom adapted to abut the inner surface of the end 20 of head 19. Thus sleeve 25 is loosely confined between baflle 13 and head 19. Head 19 is preferably formed by spinning up a disc of copper plate. Terminal 22 is preferably of bronze while sleeve 25 may be of plain carbon steel, as are tube 10, baffle 13 and chamber 15.

By virtue of the construction described, oxygen flowing through tube 13 divides into diverging jets on passing through tubes 24. Cooling water supplied through inlet 1'7 flows through the space between tube 10 and balfle tube 13, then through sleeve 25 and inwardly from the end thereof, then between the flange 27 thereon and the inner surface of end 20 and around the tubes 24 close to the exposed ends thereof. Adequate and effective cooling is thus assured by the rapid flow and intimate contact produced. Sealing rings 23 and brazed joint 21 prevent leakage of water into terminal 22 or from the end of chamber 15. Nevertheless, the nozzle may be easily removed as a unit from the lance formed by tube 10 and chamber 15, by turning off the metal of joint 21. A replacement nozzle may then be slipped in place and brazed fast.

Figures 4 and 5 show a modification closely similar to the construction described above except that the nozzle head 30 is cast integral with terminal 31 and diverging jet tubes 32 connecting them. The head is screwed into the end of chamber 15 and an internal annular shoulder 33 at the rear end of the head fits on the end of baffle 13. Holes 34 are spaced circumferentially around the shoulder to permit return flow of cooling water from the head through chamber 15. A sleeve 35 seated in the shoulder 35 extends forwardly around terminal 31 to a plane closely adjacent the extreme end of the nozzle head. Sealing rings 36 and 37 close the joints between the baflle tube and shoulder 33 and between the oxygen tube 10' and hub 31, respectively.

It will be evident that the cast nozzle of Figures 4 and 5 has the same advantages as the fabricated construction shown in Figures 1-3.

Although I have disclosed herein the preferred embodiment of my invention, I intend to cover as well any change or modification therein which may be made without departing from the spirit and scope of the invention.

I claim:

1. A fluid-cooled nozzle comprising a supply pipe having one end connected to a fluid source, a hollow cupj a 3 shaped terminal slidable ori the discharge end of the pipe, a cylindrical water jacket surrounding and coaxial with said pipe and extending therealong to a point adjacent the discharge, end thereof, a hollow cup-shaped shell rerri ovablyrriounted on the foi'war'd end of said jacket and spaced radially from said terminal, a jet tube eitendin'g through the endwall of the terminal and through the end wall-of the shell, exposed to cooling fluid transversing said jacket, *and a battle tube coaxial with said pipe and jacket, intermediate the latter, spaced radially from both and extending therebetween to a point adjacent the end wall of saidshell.

2. A nozzle as defined by claim 1, characterized by an extension sleeve on the forward end of the bafiie tube, said extension having at its forward end an inturned flange notched to receive said jet tube.

ReferencesCited in the tile of this patent UNITED STATES PATENTS 1,850,227 Dinner Mar. 22, 1932 

